Talk:Pi ship

Lacking space, Silver only talks about it, but Michael Hogg's (www.michael-hogg.co.uk) gol page shows a nice [unnamed] pi type ship. Should it be duplicated here ? --Methodood 21:42, 9 December 2009 (UTC)

there isn't even a page for "pi ship" much less an image.

I'm pretty sure that the most well known pi ship is the one on Hogg's page. It can be seen in the 'Cambrian explosion' pattern that comes with Golly. I am not sure who discovered this pattern or when it was discovered, however (I believe that the 3c/10 pi crawling reaction has been known for a long time).

P.S. to St Thomas : more precisely stated, it's the "Unnamed Pi Ship 1" in the "Pi Ship" type. --Methodood 22:26, 10 December 2009 (UTC)

3c/10 ship

It is not a great leap of imagination to consider the possibility of a purely 3c/10 spaceship. Indeed, people looked for ways to amalgamate multiple pi crawlers into a single spaceship. Alas, no-one has yet accomplished this feat.

I would imagine that a working pi ship would be shaped like a parabola:

*         oooooo
*      ooo      ooo
*     o            o

In the centre, forward gliders are produced from pi interactions. However, the gliders advance slower than the ship itself, so they will slowly propagate backwards relative to the ship. The gliders then hit the ends of the ship in order to stabilise them.

There is one problem: the gliders will hit the inner side of the pies, when it is the outer side that lacks stabilisation. If there is not a simple solution, one may have to resort to a Caterpillar-like spaceship with helices and fanout devices.

In order for any of these ideas to work, there needs to be a way for 3c/10 pies to interact, non-destructively, to produce gliders. No such reaction is known.

--Calcyman 17:07, 10 December 2009 (UTC)

It is noted that "The front part of this Pi Ship is an Unnamed Line Puffer 1 (p18, moving at c/2), while the back part is an Unnamed Pi Track 1 (p30, moving at 3c/10)". I believe that, whatever the speed, it is not a real ship because it stretches.

- Is there a name for that type ?--Methodood 22:26, 10 December 2009 (UTC)

They are generally referred to as growing spaceships. We have only one on the wiki so far, blinker ship 1.
~Sokwe 23:25, 10 December 2009 (UTC)

Pi ship - category or pattern?

According to Stephen Silver's Life Lexicon, a pi ship is any growing spaceship in which the back part consists of a pi-heptomino travelling at a speed of 3c/10. Although the c/2 front end is the most well known, it certainly isn't the only possible front end. Here's a pi ship with a c/3 front by Nicolay Beluchenko:

x = 84, y = 48, rule = B3/S23
8b3o17b3o$3b2ob2obo19bob2ob2o$3b2o4bob2o13b2obo4b2o$2bo2bo3bobobo11bob
obo3bo2bo$9bobobob2o5b2obobobo$7bo3bobob2o5b2obobo3bo$8bobobob3o5b3obo
bobo23b2o17b2o$49bob2ob2o17b2ob2obo$12b3o9b3o21b3obo3b2o13b2o3bob3o$
12b3obobobobob3o20bo3b2obobobo11bobobob2o3bo$13b5obob5o22bo3b3obob3o7b
3obob3o3bo$18bobo31bo3bobob2o5b2obobo3bo$18b3o32b2obo5bo3bo5bob2o$15bo
bo3bobo35bo9bo2$13b2ob3ob3ob2o30b3obo3bo3bob3o$13bo11bo32bo2b2obob2o2b
o$12bo2bo7bo2bo34bo2bo2bo$12bo4bo3bo4bo33b2o5b2o$17bo3bo38b4ob4o$11b6o
5b6o$10b2o7bo7b2o29b3ob2ob2ob3o$18bobo36bo4b2ob2o4bo$18b3o39b3o3b3o$
57b4obo3bob4o$7bo49b5o5b5o$5b4o46b2o5bo3bo5b2o$b2ob2o3bo3bo$b2o2bo5b4o
3b3o34bo5bo2bo2bo5bo$o2bo7bo3bo3bo39bo3bobo3bo$9bo2bobo3bobo15b3o24bob
o$10bo8bo15bo3b2obo21bo$19bo10b3o2b3o3b3o31b3o$29bobob3o4bo3bo29bo3b2o
bo$29bobo3bo7bo25b3o2b3o3b3o$33b2o28b3o2bobob3o4bo3bo$69bo4bo7bo$44b3o
25b2o$30bo9bob2o3bo$31bo7b3o3b3o2b3o$23b2o3b3o7bo3bo4b3obobo5bo$29b2o
8bo7bo4bo4b3o$48b2o6bob3o4b2o$55b2o3bo3b3o$41bo14b3o8bo$40bobo14b2o$
40bobo$40bobo!

I suggest that the pattern be moved to pi ship 1, and this page be changed to a more general definition of "pi ship" (probably with a note on the theoretical spaceship based on this reaction).

Also, The pattern image will not appear in the infobox unless the parameter rle = true is included. This will create a link to the pattern in the conwaylife.com database. You can add patterns to the database using the Java applet at http://conwaylife.com/; however, This will not add them to the official pattern database (this must be done by one of the conwaylife.com forum moderators or Nathaniel). For more information on creating and editing pattern pages, see LifeWiki:Pattern_pages.
~Sokwe 03:01, 14 May 2010 (UTC)

There, I've moved the page. Keiji 16:02, 14 May 2010 (UTC)